regimen

Merriam-Webster's Word of the Day for October 6, 2026 is: regimen • \REJ-uh-mun\  • noun Regimen refers to a plan or set of rules about food, exercise, etc., designed to make someone become or stay healthy. // Sherry’s personal trainer started her on a workout regimen of 30 minutes on the treadmill followed by 30 minutes of weight training. See the entry > Examples: "The last step in a great antiaging skin care regimen is, of course, sunscreen." — Alanna Martine Kilkeary, Glamour, 27 Apr. 2026 Did you know? Being but humble lexicographers, we cannot say whether an apple a day truly keeps the doctor away, but as far as regimens go, one could do a lot worse than snackin' on a McIntosh. Regimen, which usually refers to a system of rules or guidelines—often for living a healthy life or taking a regular dose of exercise—comes ultimately from a Latin verb, regere, meaning "to direct." Regere led in apple-pie order to the English word regimen, first by way of the Latin noun regimen, meaning "steering" or "control," and then via the Medieval Latin regimen, referring to a set of rules. Other regere descendants fell further from the tree, including correct, erect, region, rule, and surge. Be sure not to confuse regimen with regiment, which refers to a military unit, as doing so could upset the apple cart.